1. Field of the Invention
The present invention relates to a probe structure. More particularly, the present invention relates to a split-type probe.
2. Description of Related Art
A semiconductor package test can be mainly divided into two parts, namely, wafer probe and sort after wafer processing, and final test after packaging. In the wafer probe and sort, a probe of a wafer probe card on a wafer prober is used to connect to a pad of each of dies on a wafer under test. Then, data measured are transmitted to a tester for making analysis and determination to obtain repairable data of each die. According to the repairable data, a test man can use a laser-repair machine to replace defect elements, and it is finished after passing the test.
FIG. 1 is a structural view of a conventional wafer probe card. Referring to FIG. 1, a conventional wafer probe card 100 includes probes 102, 114, 116, and a circuit board 104. According to a current technique, the circuit board 104 usually adopts a fly-by structure, that is, signal transmission lines 106, 108 connected to each other by a connecting plug 110 are respectively disposed on two surfaces of the circuit board 104.
In the conventional art, one end of the probe 102 is connected to the connecting plug 110, and another end is used to contact with dies of a wafer under test (not shown). In addition, one end of the probe 114 and one end of the probe 116 are grounded or connected to a common voltage through connecting plugs 122 and 124, and another end of the probe 114 and another end of the probe 116 are used to contact with the object under test.
In the conventional wafer probe card 100, the test end generates a testing signal to the signal transmission line 106 of the circuit board 104, and transmits the testing signal to the wafer under test through the probe 102, such that the object under test generates a response signal. In addition, the probe 102 can receive the response signal generated by the object under test, and transmits the response signal to the test end through the signal transmission line 108, so as to obtain the electrical characteristic of the object under test.
FIG. 2A is a waveform diagram of the voltage vs. the time of the testing signal during transmission according to the conventional art. Referring to FIG. 2A, the longitudinal axis is the voltage, and the horizontal axis is the time. In addition, the waveform 201 is the waveform of the testing signal measured at the circuit board end, and the waveform 203 is the waveform of the testing signal measured at the contact end of the probe. As shown in FIG. 2A, when the circuit board transmits a testing signal to the object under test through the probe, the signal attenuation amount is limited.
FIG. 2B is a waveform diagram of the voltage vs. the time of the response signal during transmission according to the conventional art. Referring to FIG. 2B, similarly, the longitudinal axis is the voltage, and the horizontal axis is the time. In addition, the waveform 211 is the waveform of the response signal measured at the contact end of the probe, and the waveform 213 is the waveform of the response signal measured at the circuit board end. As shown in FIG. 2B, the maximum voltage of the response signal at the contact end, e.g. A point, is approximately 750 mV. When the response signal is transmitted back to the circuit board by the probe, the maximum voltage, e.g. B point, is approximately 500 mV. High signal attenuation results in the error of the test end when performing determination, and the signal attenuation is more distinct during high-speed signal transmission. The object under test can be a semiconductor device or each die on the wafer.